package com.yql.reggie.controller;

import com.yql.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件上传与下载
 */

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file)  {
        //当前file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
        log.info(file.toString());

        //截取原始文件名后缀
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));

        //使用UUID随机生成文件名 防止文件名重复造成文件覆盖
        String fileName = UUID.randomUUID().toString() + suffix;

        //创建一个目录对象
        File dir = new File(basePath);
        //判断目录是否存在
        if(!dir.exists()){
            //目录不存在，创建目录
            dir.mkdir();
        }


        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param httpServletResponse
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse httpServletResponse){

        try {
            //输入流， 通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));

            //输出流，通过输出流将文件写回到浏览器，在浏览器里展示
            ServletOutputStream outputStream = httpServletResponse.getOutputStream();

            httpServletResponse.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes, 0, len);
                outputStream.flush();
            }

            outputStream.close();
            fileInputStream.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}
